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Axion 3D Atlas
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military.txt
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1998-01-23
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{bigtext=20,85,"Military Satellites"}
{4}Many satellites have military uses too. Comsats are used to keep armies and
military bases in touch, and to pick up signals from secret agents with
transmitters or automatic ground spying equipment. Their messages are scrambled
so that only some receivers can decode them. Metsats predict the weather for
army exercises and tell military planners when an area will be clear of cloud
so a spy satellite can film it. Countries are very secretive about their
military satellites even civilian satellites are sometimes secretly fitted with
small extra devices for military use.
To see the orbit of a real Russian spy satellite (Cosmos 2278), click {s,"13,2",here}{4}!
Spy Photography
Satellites can spy on countries without being harmed. Some use real film
because it provides a more detailed image that TV pictures transmitted by electrical
signal. They jettison the film in a heat-proof capsule. The capsule's re-entry
path is carefully planned, and an airplane picks it up as it falls. Spy satellites
sometimes carry infra-red sensors that transmit images in digital form. The
cameras on spy satellites are so good that it's photographs show up people on
the ground from over 100 miles up.
Radar Spy Satellites
Radar satellites keep watch on moving targets, like warships. One kind is nuclear-
powered, generating enough electricity to drive a very powerful radar. After its
mission, a radio signal from the ground orders the satellite to split into pieces.
The nuclear section has its own rocket motor to boost it into high orbit where it
should stay for 600 years.
Other types of spy satellites carry radio receivers to listen in to enemy radio
and radar signals. They are called "ferrets".
Early Warning
Early Warning satellites carry infra-red sensors to detect the hot exhaust of a
nuclear missile. They carry equipment to transmit photos of the missiles at
the same time, to prove the satellite has not made an error. They can detect a
missile within seconds of ignition. Equipment for early warning can be fitted to
ordinary military or civilian satellites.